Many integrated circuit devices employ memory devices to store data. The memory devices are typically composed of bit cells, with each bit cell storing one or more bits of data. In order to read the value of data stored at a bit cell, a signal generated by the bit cell in response to application of a read voltage is compared at a sense amplifier to a reference signal provided by a reference device. The reference device can include a transistor having similar characteristics as the bit cell transistor, allowing it to track the characteristics of the bit cell transistor.
As power specifications for memory devices have become more stringent, the range of signal magnitudes representing different logic states has grown smaller. In addition, the difference in magnitude between a signal representing a designated logic state and the signal generated by the reference cell has become smaller. Accordingly, it can be difficult for a sense amplifier in a conventional configuration to accurately sense a difference between the reference signal and the signal generated by the bitcell. Therefore, an improved device for sensing the state of a bitcell would be advantageous.